In the course of scuba diving and snorkeling, small amounts of water seep or leak into a diver's face mask. This creates an annoyance since the water can obscure the diver's vision, or enter a diver's mouth or nose.
Face masks have been provided with a purge valve in front of the nose, mouth or chin for discharge of water by exhaling. Water escapes through a mushroom valve formed by a flexible elastomeric valve cover with an elongated valve stem extending through an aperture formed in a valve cover support. Upon vigorous exhaling, the flexible valve cover opens and the water is forced out of the mask along with the exhaled air.
The above face masks have been generally well received. However, the release of the air bubbles centrally of the face mask caused the visual field to be obscured by the rising bubbles. Since purging is required fairly often, this can be annoying. In some instances it can create a safety problem where accurate vision is particularly required as in welding and other underwater working activities.
In an effort to solve this problem, a deflector was provided to channel bubbles released during purging to either side of the mask to avoid bubbles in the central vision of the mask. Such a mask is the subject of U.S. Pat. No. 4,856,120.
The above described face mask, while a vast improvement over the central purge valve masks without the deflector, requires that the head be held level for accumulation of water in the central area of the mask. This is not always possible or convenient.
There remains a need for a diver's face mask which would be easily and effectively purged without obscuring the visual field during purging.
Another problem is that centrally oriented purge valves do not always gather water in the area to be purged. The diver's face mask of this invention allows the flow of water to an offset sump above the purge valve for improved gathering of water. This in part is accomplished by merely inclining the head of a diver to gather the water in the sump.
Thus, it is an object of the invention to provide a diver's face mask having a centrally offset purge valve which is easily purged by tilting the mask toward the purge valve to accumulate any water within the mask into a sump and exhaling to drive it out of the mask.